                      (if (= :put wait-kind)
                        ["<line x1='500' y1='" (* actx-position line-height)
                         "' x2='600' y2='" (* ch-position line-height)
-                        "' stroke='green' stroke-width='1' marker-end='url(#triangle)'/>"]
+                        "' stroke='green' stroke-width='" stroke-width
+                        "' marker-end='url(#triangle)'/>"]
                        ["<line x1='600' y1='" (* ch-position line-height)
                         "' x2='500' y2='" (* actx-position line-height)
-                        "' stroke='red' stroke-width='1' marker-end='url(#triangle)'/>"])))
+                        "' stroke='red' stroke-width='" stroke-width
+                        "' marker-end='url(#triangle)'/>"])))
                  wait-chs)))
         (:actxs vis))])
 

      (let [[actx event] (<! event-ch)
            [verb step & args] event
            vis-event-handler (get (get vis-event-handlers verb) step)
            positions (atom {})]
        (vis-event-handler vis actx args)
        (let [actx-ch-ch-infos (group-by #(:first-taker-actx (second %)) (:chs @vis))]
          (set-el-innerHTML "vis-html"
                            (apply str (flatten (vis-html-actx @vis @root-actx positions
                                                               actx-ch-ch-infos))))
          (set-el-innerHTML "vis-svg"
                            (apply str (flatten (vis-svg-actxs @vis @positions))))
          (set-el-innerHTML "event"
                            (str num-events ": " (last actx) " " verb " " step " " args))))
      (recur (inc num-events)))
    (ago w-actx w
         (reset! root-actx w-actx)
         (let [in (achan-buf w-actx 100)

                actx-position (+ 0.5 (get positions actx-id))
                wait-chs (:wait-chs actx-info)
                chs (:chs vis)
                line-height 21
                stroke-width 1]
            (map (fn [kv]
                   (let [[ch wait-kind] kv
                         ch-info (get chs ch)
